Existing Aviva customers who want to move to AvivaPlus can do so without paying a cancellation fee, the insurer said.

New industry rules to help insurance customers shop around and increase transparency around pricing were introduced in April 2017.

They require firms to clearly show the insurance premium a customer paid the previous year, alongside their proposed renewal premium.

But in April 2018, the Financial Conduct Authority (FCA) said it had found some firms were still failing to properly implement the rules.

In September, the Competition and Markets Authority (CMA) said it would investigate concerns that people who stay with their provider can end up paying significantly more than new customers.

The CMA received a super-complaint from Citizens Advice about long-term customers overpaying for key services such as household insurance, broadband and savings accounts.

Rachel Springall, a finance expert at Moneyfacts.co.uk, said of the new product, which will have simplified language: “This latest initiative by Aviva will likely attract consumers who hope to be treated fairly on renewal and want peace of mind that they will be offered a good quote, thanks to the renewal price guarantee.

“Not only this, but the efforts of Aviva to make picking a policy less of a burden may well encourage consumers to take more time to reassess their policy and all of its benefits thanks to more simplified wording.”